In a large bowl, combine oatmeal, rice cereal and dried cranberries. Set aside.
In a small saucepan, combine corn syrup and brown sugar. Heat over medium/high heat until it begins to boil. Remove from heat. Add to sugar mixture; peanut butter and vanilla extract. Mix well. Pour mixture over dry ingredients and mix well.
Press into 13x9 inch pan, and let cool. Cut into squares and enjoy!